1. Field of the Invention
The invention relates to a connector and a construction for preventing a terminal fitting from shaking in a connector housing.
2. Description of the Related Art
A conventional connector housing has opposite front and rear ends and a cavity that penetrates through the housing from the rear end to the front end. An elastic locking piece is cantilevered obliquely and forwardly from a wall of the housing into the cavity. A terminal fitting can be inserted into the cavity from behind and locked into engagement with the leading end of the elastic locking piece.
Some connectors are used in high vibration environments, such as in automotive vehicles. Vibrations in these environments cause mated terminal fittings to rub against each other at a high speed and can abrade the contact portions. Fine sliding abrasion can be restricted by preventing vibration of the terminal fittings in the cavities. Therefore, suitable members may be held in contact with the terminal fittings to prevent vibrations.
Some known connectors prevent fine sliding abrasion by pressing the barrel of the terminal fitting or by pressing the insulation coating of the wire. However, these connectors still have problems. Specifically, the same terminal fitting may be used to connect wires that have different diameters. In this case, a contact member for pressing the wire may not contact the wire, depending upon the diameter of the wire. Similarly, the height of a barrel that is crimped into connection with a core or an insulation coating of the wire will vary depending on the diameter of the wire. Thus a contact member for contacting the barrel may not reach the crimped barrel. In these situations, the problem of fine sliding abrasion cannot be solved.
Some connectors include both elastic locking pieces and a retainer for securely locking terminal fittings in a connector housing. An example of such a connector is disclosed in Japanese Unexamined Patent Publication No. 11-204185 and is illustrated in FIG. 20 herein. The connector of FIG. 20 includes a terminal 50 and a connector housing 51. The connector housing 51 is formed with a cavity 52 that has a front wall 53. The terminal 50 can be inserted into the cavity 52 in a rear-to-front direction until the terminal 50 engages the front wall 53 of the cavity 52. A cantilever-shaped lock 54 extends from a bottom wall of the cavity 52 to elastically engage and lock a bottom side of the terminal 50. A retainer 55 is mounted on the upper surface of the connector housing 51 to engage and lock the upper surface of the terminal 50. Thus, the terminal 50 is prevented from backing out of the cavity 52.
The connector of FIG. 20 has a problem because the terminal 50 shakes in the cavity 52. The shaking occurs because the lock 54 is elastically deformed downward when the terminal 50 is inserted. At this time, an engaging position of the lock 54 moves in an arc. Accordingly, the engaging position of the lock 54 differs in a horizontal direction by a specified distance between a position where the lock 54 permits the terminal 50 to pass and a position where the lock 54 is restored elastically to its original shape to lock the terminal 50. This creates a clearance between the terminal 50 and the lock 54 in a state where the lock 54 locks the terminal 50, although this clearance is very small.
The retainer 55 is mounted by pushing straight into the connector housing 51 for mounting. Accordingly, no clearance is formed for the same reason as the lock 54. However, the retainer 55 is formed separately from the connector housing 51, and unlike the lock 54, must create clearances (a) and (b) at a retainer mount position in the connector housing 51 for manufacturing or assembling reasons when the retainer 55 is assembled with the connector housing 51. Thus, the mount position of the retainer 55 varies in forward and backward directions because the retainer 55 is assembled with the connector housing 51, and clearances exist between the terminal 50 and the retainer 55.
The prior art locking construction of FIG. 20 cannot avoid the shape of the terminal 50 in the cavity 52. The use of such a connector in an automotive vehicle will cause vibrations to be transmitted from the vehicle to the connector. Thus, the terminals will shake at a high speed and abrade due to fine sliding.
The present invention was developed in view of the above problems and an object of the invention is to prevent a terminal from shaking in a cavity.
The invention is directed to a shake preventing construction for a terminal fitting. The construction comprises at least one terminal fitting with a wire connecting portion at one end for connection with a wire. The connector further has a connector housing with at least one cavity for accommodating the terminal fitting. A terminal fixing device is mountable in the connector housing and has a contact portion for contacting the terminal fitting before or near the wire connecting portion to prevent the terminal fitting from shaking. Accordingly, fine sliding abrasion with a mating terminal can be avoided.
The contact portion of the terminal fixing device contacts the terminal fitting at a position spaced from the wire connecting portion, and therefore is not affected by different diameters of wires to be connected. As a result the terminal fitting can be prevented from shaking with a high degree of reliability.
The terminal fixing device preferably comprises a locking portion for locking the terminal fitting in the cavity. Accordingly, the contact portion of the terminal fixing device prevents the terminal fitting from shaking, while the locking portion of the terminal fixing device prevents the terminal fitting from coming out.
The terminal fixing device preferably is formed with a front-stop wall. The front end surface of the terminal fitting can be brought into contact with the front-stop wall for determining a front end position of the terminal fitting. Accordingly, the contact portion of the terminal fixing device prevents the terminal fitting from shaking, while the front-stop wall of the terminal fixing device determines the front end position of the terminal fitting.
The terminal fitting has a connecting portion for connection with a mating terminal fitting. The terminal fitting also may comprise a receiving piece between the connecting portion and the wire connecting portion. The contact portion of the terminal fixing device contacts the receiving piece to prevent shaking of the terminal fitting.
At least one of the terminal fitting and the contact portion of the terminal fixing device may be formed with a guide surface for guiding a locking operation of the terminal fixing device.
The terminal fixing device can be positioned in a partial lock position, such that at least one communication hole in the terminal fixing device substantially aligns with the corresponding cavity. Thus, the terminal fitting can be inserted into the cavity and the communication hole. The contact portion contacts the terminal fitting when the terminal fixing device is in the full locking position to lock the terminal fitting in the cavity.
One contact portion may enter at least two adjacent or neighboring cavities when the terminal fixing device is in the full locking position. Additionally, corresponding opening edges of the communication hole enter the cavity when the terminal fixing device is in the full locking position.
The terminal fitting may be provided with locking means for interacting with mating locking means in the connector housing to provide secondary locking for locking the terminal fitting in the connector housing.
The invention also is directed a connector with a shake preventing construction. The connector comprises at least one terminal fitting with an engaging portion in a position spaced backward from a leading end of the terminal fitting by a specified distance. The connector also comprises a housing with at least one cavity for accommodating the terminal fitting along its longitudinal direction. The cavity may have an opening for exposing the engaging portion to the outside. A terminal retainer is mountable into the housing and has a front-stop wall substantially at the front end of the cavity and held substantially in contact with the leading end of the terminal fitting. The terminal retainer is provided integrally or unitarily with a terminal locking portion spaced backward from the front-stop wall by a specified distance and engageable with the engaging portion.
The specified distance by which the engaging portion is spaced from the leading end of the terminal fitting preferably equals the specified distance by which the locking portion is spaced from the front-stop wall. Thus, the dimensional variations in forward and backward directions provided for manufacturing or assembling reasons in the prior art can be made smaller and, therefore, the shake between the terminal fitting and the terminal locking portion can be suppressed to a maximum extent. As a result, the connector is effective against fine sliding abrasion.
The engaging portion of the terminal fitting and/or the terminal locking portion of the terminal retainer preferably is formed with a guide surface for guiding a locking action of the terminal locking portion of the terminal retainer. Accordingly, the terminal locking portion performs its locking action smoothly.
The terminal retainer is movable between a partial locking position where it is held in the housing so as not to hinder insertion of the terminal fitting into the cavity and a full locking position where the terminal locking portion engages the engaging portion of the terminal fitting to prevent the terminal fitting from coming backwardly out of the cavity.
These and other objects, features and advantages of the present invention will become more apparent upon a reading of the following detailed description and accompanying drawings.